Earlier this week, Steve Waugh, a decent judge of the game of cricket, said Virat Kohli will break all batting records, barring Don Bradman’s batting average of 99.94 in Test matches.

In the same week, Kohli turned 30—a mid-point of sorts in cricketing careers, and the beginning of a decade that is fascinating for what it has come to mean for top batsmen.

The first half of the 30s is prime time. The eyes are sharp, the feet are moving, the body is supple, the mind is willed, the years count for a lot.

But in the second half, time starts to chip away at those batting essentials, and the descent to something less than prime is silent, pronounced and poignant.

For example, among the top four run-getters in Tests, Sachin Tendulkar retired at 39, Ricky Ponting at 38, Jacques Kallis at 38 and Rahul Dravid at 39. And each endured significant battles with time near the end of their careers.

These four were also some of the most prolific batsmen in their 30s. There were others as well. There was one set that made a comeback in their 30s, and compressed an entire career in seven or eight years.

There was another set that played on and on, and crafted a career of competence. In the context of Kohli’s many batting pursuits, it is useful to see who these batsmen are and the markers they laid down for the 30s. Take maximum runs in Test matches, the most important batting record in all of cricket.

At present, it is also the Mount Everest of batting records. Kohli has 6,331 runs from 75 Test matches, and he’s ranked 57.

Tendulkar, with 15,921 runs from 200 Test matches, holds that record. For Kohli, that’s another 9,590 Test runs and, suddenly, Waugh’s prophecy already looks very far. It seems even farther, given the maximum Test runs scored by any batsman in their 30s: 7,674 runs by Dravid at 51.5 runs per innings (chart 1).

Only 26 batsmen have scored above 5,000 runs in their 30s. Among the top-10 run accumulators in the 30s, there are interesting sidelights. Six of the top 10 run-getters of all-time feature in this list. There’s No. 1 (Tendulkar), two (Ponting) and four (Dravid), and each averaged less in their 30s than over their careers. None more so than Tendulkar, who averaged nearly 4 fewer runs below his career average of 53.78.

The other seven in the top 10 list bettered their career average. Matthew Hayden (7,306 runs) is the second highest run-scorer in the 30s. Hayden debuted at 23, barely played for his first six years, made a comeback at 29 and played continuously for 10 years. Barring Tendulkar, who debuted at the age of 16 years, the top batsmen with long careers tend to score more than half their runs in their 30s. For example, Dravid scored 58% of his runs in his 30s, Ponting 52% and Kumar Sangakkara 56%. If Kohli is to challenge Tendulkar’s record, he would look to emulate Sangakkara, who also scored runs in his 30s at an average of 60—the most by any batsmen among the top 10.

In one-day internationals (ODI), Kohli is relatively better-placed, but he still has to bat better than most have done in their 30s. Kohli has 10,232 ODI runs. He is currently the 12th highest run-getter of all time, and is climbing at an audacious pace. Kohli averages 59.83 in ODIs so far. The next best among those ahead of him in ODI runs is 44.83—a full 15 runs less per innings. That next best is Tendulkar, and he holds the record for most ODI runs as well: 18,426 runs.

In other words, Kohli is 8,194 runs short. To get past, Kohli will have to be the fourth most prolific run-scorer in the 30s. A troika of Sri Lankan batsmen—Sanath Jayasuriya, Tillakaratne Dilshan and Kumar Sangakkara—have scored more than 8,000 ODI runs in their 30s. In ODIs, only 15 batsmen have scored more than 5,000 runs in their 30s, which says something about the challenges of longevity in the shorter version. Kohli is fit and hungry. But he’s also entering the decade for batsmen that can be generous when it rewards and brutal when it punishes.